Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c3b61f91ed18479…

MALICIOUS

PDF

88.0 KB Created: 2021-07-04 12:05:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4e414c239eefbde85e584952c3839590 SHA-1: ac4bb6b281d10606a6246acdf7500714ecfca937 SHA-256: 5c3b61f91ed18479daa8bc859aa333dee830a133b4e45129ca8efc50c8c0ab48
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm with numerous URLs pointing to other PDF files hosted on compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple links on disposable hosting and compromised CMS uploads reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://nowyhotelik.pl/userfiles/file/sirefebuzezaxumenenot.pdf
    • http://expertsystemgroup.com/file_media/file_image/file/83652343659.pdf
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/2dgve0qac8a1otjs7on21jeb6g/kufebozudetuferes.pdf
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c18787148f5---vuseguzove.pdf
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f0f5760c55---98231866404.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160cd009279784---87547304347.pdf
    • https://studio-september.com/wp-content/plugins/super-forms/uploads/php/files/8623bf77d29c0325fc42f876188ea653/zopomareba.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0ae048c699---48584124608.pdf
    • https://alakharia.com/public_html/userfiles/file/2131508533.pdf
    • https://muzeumkonstancina.pl/attachments/file/75689063696.pdf
    • https://festival.bg/fckeditorfiles/file/15924474312.pdf
    • http://kasargod.net/uploads/file/34684795466.pdf
    • http://worthingtonpark101.com/userimages/kuzodolanimusewezizixe.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/7qplr85mcj6icv57epjs4psm59/19469259215.pdf
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/e5v2qt1vp6c64nop51ctmm6lqt/83962044339.pdf
    • http://elitakhealing.com/ckfinder/userfiles/files/rebipipolamapilukuk.pdf
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/16081a8a5e55e2---xalajesageveradurupelamif.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160dd84ce50fc0---mikibezalifumopulov.pdf
    • http://nuraski.pl/wsg/userfiles/39736110141.pdf
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ef00eef4d0---17453234106.pdf
    • http://alt-1c.ru/userfiles/file/20977531027.pdf
    • http://weclassof86.com/clients/6/6d/6dc59c75684a9be5e3a4726337e2fa3a/File/gumuneridu.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608937a1a7b72---62907371205.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/uq302rmduoa3jmms954d9f0qb2/46215970570.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=victory+in+jesus+travis+cottrell+chords
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e01f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE01F 16792 bytes
font_01_sfnt_off0000f836.bin
34732d43a9ccb7559b4f12425598901bacd44c8db24de6944c22afb9e0a79b27
pdf-font-stream PDF embedded font (sfnt) at offset 0xF836 10844 bytes
font_02_sfnt_off00011134.bin
27fa49ca30b1f57c6e4f8b99ad1f73ead7010ce1f191e20d716503af09158f46
pdf-font-stream PDF embedded font (sfnt) at offset 0x11134 16160 bytes
font_03_sfnt_off000126a9.bin
ea44a7a3f7619d7e9b6c2d5379d5703917ce82afab4444330587d1e90c5ce46e
pdf-font-stream PDF embedded font (sfnt) at offset 0x126A9 16660 bytes